Nantucket Shoals

Nantucket Shoals is an area of dangerously shallow water in the Atlantic Ocean that extends from Nantucket Island, Massachusetts, eastward for 23 miles (37 km) and southeastward for 40 miles (64 km); in places water depth can be as shallow as 3 feet (0.91 m).[1] Depth soundings are unpredictable due to constant change from strong currents, which are rotary rather than reversing.[2] The shoals lie just off a major transatlanticshipping lane. Numerous ships have been wrecked here, most recent and notably the oil tankerArgo Merchant in December 1976. Until 1983, the edge of the shoals was guarded by the Nantucket Lightship.